87 740 turbo wagon.

Trying to decide on springs and dampers for my wagon.
Done a lot of reading, and I'm pretty torn which way to go still.

I like the look of lowering a bit, there are lots of options for springs.
The concern is for one I tend to drive my cars like a truck, I don't care to slow down for speed bumps and train tracks, within reason. For two, as prone as these cars seem to be to front end shimmys and driveshaft vibration, I'm hesitant to muck with the factory suspension geometry. As it is now my slightly sagging rear has the driveshaft bumping a little on takeoff, and it's worse loaded. When the suspension is done if it's still there I will look into shimming the center support as Volvo advised, but I don't want to make it worse. IPD has the adjustable panhard rod to keep the rear centered at least, but a lot of people report problems with this.

So, 2nd thought.
Overload springs for the rear.
I like to be able to haul stuff. The factory rear springs are either toast or they were too soft to start with it seems to me. But, I don't think the Boge Turbo-Gas dampers I'm leaning toward can handle those springs, especially unloaded, I've found more than a few accounts of this. Even the $$$ Bilstien HD's aren't really up to it on the rebound damping, and I'm just not spending the money for adjustable Koni's or the like. FCP has some presumably softer overload springs by Moor or somebody, I can't find a lot fo input on them though.
For the front, which aren't sagging really but I want to replace them while I have it all apart as cheap as they are. I've wondered about the heavier factory springs, such as a diesel had, one of the parts sites lists spring wire diameter, I am yet to measure mine and see what it has from the factory. I don't really want to raise the front any though. I guess the semi-safe bet is just the scantech plain jane front springs, surely they can't screw up manufacturing a coil spring.

Essentially I want stiffer springs all around with the stock ride height, that aren't too stiff for Boge Turbo-Gas dampers to be able to handle.

Opinions, experience?